Communication method, wireless base station, server, and wireless distribution system

1. A communication method of a server that transmits a packet by multicast or broadcast via a wireless base station to at least one or more wireless terminals connected to the wireless base station via a wireless network using a channel, the method comprising: generating, via a processor, the packet including priority data indicating a priority has been set beforehand, the priority data of the packet indicating a first priority; acquiring, via the processor, channel-used time that is time over which the channel is used per unit time at the wireless base station; calculating, via the processor, channel-usable time that is time over which the channel is available to be used per unit time, for the wireless base station to transmit the packet to the wireless terminal, based on the channel-used time; calculating, via the processor, a first channel usage estimated time that is time estimated to be used for the wireless base station to use the channel to transmit the packet to the wireless terminal; calculating, via the processor, a wireless transmission rate to be applied when the wireless base station transmits the packet to the wireless terminal, based on the priority indicated by the priority data included in the packet, to where the first channel usage estimated time is within the channel-usable time; transmitting, via a transmitter, the packet, and information indicating the wireless transmission rate, to the wireless base station; and transmitting, via the wireless base station, the packet to the wireless terminal in accordance with the calculated wireless transmission rate, wherein another packet including different priority data indicating a second priority different from the first priority is transmitted at a different wireless transmission rate.

2. The communication method according to claim 1 , further comprising: setting, via the processor, an initial value for the wireless transmission rate, wherein, in the calculating of the wireless transmission rate, the initial value of the wireless transmission rate is changed based on a priority indicated by priority data included in a particular packet, in a case where the first channel usage estimated time exceeds the channel-usable time.

3. The communication method according to claim 2 , wherein, in the generating, a plurality of packets are generated, each packet among the plurality of packets including priority data indicating different priority from other packets, wherein, in the calculating of the first channel usage estimated time, the first channel usage estimated time is calculated by estimating time of the wireless base station using the channel to transmit the plurality of packets to the wireless terminal, and wherein, in the calculating of the wireless transmission rate, in a case where the first channel usage estimated time exceeds the channel-usable time, the particular packet including the priority data of which the priority is lowest is extracted from the plurality of packets, and the initial value for the wireless transmission rate corresponding to the particular packet is changed to a higher value.

4. The communication method according to claim 2 , further comprising: calculating, via the processor and after changing the wireless transmission rate in the calculating of the wireless transmission rate, a second channel usage estimated time that is estimated time of the wireless base station using the channel to transmit the plurality of packets including the particular packet to the wireless terminal; and determining, via the processor, whether or not to transmit the particular packet to the wireless base station in a case where the second channel usage estimated time exceeds the channel-usable time.

5. The communication method according to claim 4 , further comprising: discarding, by the processor, the particular packet in a case of having determined not to transmit the particular packet to the wireless base station in the determining.

6. The communication method according to claim 1 , wherein, in the transmitting, an identifier indicating the wireless transmission rate is imparted to the packet.

7. A wireless base station connected to a server via a network, and connected to at least one or more wireless terminals via a wireless network using a channel, the wireless base station comprising: a receiver that receives a packet from the server, the packet including priority data indicating a first priority; a processor that determines a wireless transmission rate to be applied for the received packet when transmitting the received packet to the wireless terminal based on the priority data of the packet, different wireless transmission rates being applied to different packets of different priorities; a transmitter that transmits the packet by multicast or broadcast to the wireless terminal at the wireless transmission rate; and a measurer that measures a channel-used time at the wireless base station, the channel-used time being time where the channel is used per unit time at the wireless base station other than for transmission of the packet, wherein the wireless transmission rate to be applied to the packet is based on the priority data included in the packet and the measured channel-used time, and wherein another packet including priority data indicating a second priority different from the first priority is transmitted at a different wireless transmission rate.

8. A server that transmits a packet by multicast or broadcast via a wireless base station to at least one or more wireless terminals connected to the wireless base station via a wireless network using a channel, the server comprising: a generator that generates the packet including priority data indicating a priority has been set beforehand, the priority data of the packet indicating a first priority; an acquirer that acquires channel-used time that is time over which the channel is used per unit time at the wireless base station; a first calculator that calculates channel-usable time that is time over which the channel is available to be used per unit time, for the wireless base station to transmit the packet to the wireless terminal, based on the channel-used time; a second calculator that calculates a channel usage estimated time that is time estimated to be used for the wireless base station to use the channel to transmit the packet to the wireless terminal, and calculates a wireless transmission rate to be applied when the wireless base station transmits the packet to the wireless terminal, based on the priority indicated by the priority data included in the packet, to where the channel usage estimated time is within the channel-usable time; and a transmitter that transmits the packet, and information indicating the wireless transmission rate, to the wireless base station, wherein the information indicating the wireless transmission rate causes the wireless base station to transmit the packet to the wireless terminal in accordance with the calculated wireless transmission rate, and wherein another packet including priority data indicating a second priority different from the first priority is transmitted at a different wireless transmission rate.

9. A wireless distribution system comprising: a server; a wireless base station connected to the server by a network; and at least one or more wireless terminals connected to the wireless base station via a wireless network using a channel wherein the server includes a generator that generates the packet including priority data indicating a priority has been set beforehand, the priority data of the packet indicating a first priority, an acquirer that acquires channel-used time that is time over which the channel is used per unit time at the wireless base station, a first calculator that calculates channel-usable time that is time over which the channel is available to be used per unit time, for the wireless base station to use the channel to transmit the packet to the wireless terminal, based on the channel-used time, a second calculator that calculates a channel usage estimated time that is time estimated to be used for the wireless base station to use the channel to transmit the packet to the wireless terminal, and calculates a wireless transmission rate to be applied when the wireless base station transmits the packet to the wireless terminal, based on the priority indicated by the priority data included in the packet, to where the channel usage estimated time is within the channel-usable time, and a first transmitter that transmits the packet, and information indicating the wireless transmission rate, to the wireless base station, and wherein the wireless base station includes a receiver that receives the packet and the information from the server, a processor that determines the wireless transmission rate based on the information indicating the wireless transmission rate, and a second transmitter that transmits the packet by multicast or broadcast to the wireless terminal, at the determined wireless transmission rate, wherein another packet including priority data indicating a second priority different from the first priority is transmitted at a different wireless transmission rate.